Method for laser cutting a corneal pocket

ABSTRACT

A method for using a laser to create a pocket in a patient&#39;s cornea is provided. The pocket is created using a femtosecond or a nanosecond laser. The laser ablates tissue within the cornea in a specific shape. The shape of the pocket can be determined by software to custom program a three-dimensional path of the laser. A variety of corneal pocket configurations or computer programmed shapes can be used to accommodate various corneal lens shapes and sizes. An intracorneal lens can then be inserted into the pocket, in order to correct the patient&#39;s vision.

CROSS REFERENCE TO RELATED APPLICATION

This application claims priority to earlier filed U.S. patentapplication Ser. No. 14/852,445 filed on Sep. 23, 2015 and patentapplication Ser. No. 13/222,042 filed on Aug. 31, 2011 now U.S. Pat. No.9,168,175 and patent application Ser. No. 12/281,749 filed on Jan. 8,2009, the disclosure of each of which is hereby incorporated herein byreference, in its entirety.

FIELD OF THE INVENTION

The present invention relates generally to ocular surgery. Moreparticularly, the present invention relates to a method for lasercutting a corneal pocket.

BACKGROUND OF THE INVENTION

Presbyopia is the gradual loss of near vision. which often accompaniesthe aging process. The eyes of a person suffering from presbyopia have adiminished ability to focus on near objects such as books, magazines, ora computer screen. Symptoms of presbyopia can include difficulty readingfine print and blurred vision, when transitioning the focus of the eyebetween near and distant objects.

There are several common treatments for presbyopia. A dedicated pair ofreading glasses is one such treatment, reading glasses providemagnification of near objects to provide for improved vision. However,if a person also needs glasses to focus on distant objects switchingbetween reading glasses and distance glasses can be inconvenient.Another treatment is bifocal glasses, which provide a portion of theglasses lens for assisting with distant vision and a portion forassisting with near vision. While bifocals provide a single pair ofglasses for both near and distance vision correction, they can causedisorientation. Contact lenses for the surface of the eye have also beendeveloped which provide vision correction for both near and distancevision. Although these treatments provide vision correction for a personsuffering from presbyopia, each requires at least one an additionalaccessory or pair of contact lenses that must be worn or used daily.Additionally, very small lenses for insertion into the eye are beingdeveloped. However, a small pocket must he made in the cornea into whichthe lens can be inserted.

Accordingly, it is desirable to provide method for creating such a smallpocket in the cornea into which the lens can be inserted.

SUMMARY OF THE INVENTION

The foregoing needs are met, to a great extent, by the presentinvention, wherein in one aspect an apparatus is provided that in someembodiments includes a method tor laser cutting a corneal pocket intowhich a lens can be inserted.

In accordance with one aspect of the present invention, a method torcreating a corneal pocket includes providing a low-energy femtosecond ornanosecond laser configured to create a corneal pocket. The method canalso include positioning the laser proximate to a cornea such that itcan be used to create tile corneal pocket and determining a movementpath for the laser, in order to form the corneal pocket having aspecific pocket shape wherein the movement path follows a generallycurvilinear path. Additionally, the method can include focusing a laserbeam from the laser to a predetermined depth within the cornea betweenan anterior surface and a posterior surface of the cornea such that thelaser beam cut corneal tissue at the predetermined depth. The method canalso include moving the laser beam in the movement path in order tocreate the corneal pocket having the specific pocket shape.

In accordance with another aspect of the present invention, the methodcan include moving the laser toward the middle of the cornea tocompensate for astigmatic effect. The method can also include using alaser with an energy output in a range between approximately 0.2microjoules and 1.5 microjoules. The laser can also have a spot size ina range of approximately 0.2 to 4.0 microns and the corneal pocket canbe positioned at a depth in a range of approximately 220 microns to 350microns. Additionally, the laser with multiple laser beam spots and thespace between the spots can be eliminated. The method can furtherinclude programming the laser to create the specific pocket shape.

In accordance with still another embodiment of the present invention, amethod for creating a corneal pocket includes providing a low-energyfemtosecond or nanosecond laser configured to create a corneal pocket.The method can also include positioning the laser proximate to a corneasuch that it can be used to create the corneal pocket and determining amovement path for the laser, in order to form the corneal pocket havinga specific pocket shape wherein the movement path follows a generallycurvilinear path. The method can include using positioning software inorder to create the specific shape. Additionally, the method can includefocusing a laser beam from the laser to a predetermined depth within thecornea between an anterior surface and a posterior surface of the corneasuch that the laser beam cuts and separates corneal tissue at thepredetermined depth. The method can also include moving the laser beamin the movement path in order to create the corneal pocket having thespecific pocket shape.

In accordance with still another embodiment of the present invention amethod for creating a corneal pocket includes providing a low-energyfemtosecond or nanosecond laser configured to create a corneal pocket.The method can also include positioning the laser proximate to a corneasuch that it can be used to create the corneal pocket and determining athree-dimensional movement path for the laser in order to form thecorneal pocket having a specific pocket shape wherein the movement pathfollows a generally curvilinear path. The method can include programminga computer to control the laser such that it follows thethree-dimensional movement path to form the specific shape.Additionally, the method can include focusing a laser beam from thelaser to a predetermined depth within the cornea between an anteriorsurface and a posterior surface of the cornea such that the laser beamcuts and separates corneal tissue at the predetermined depth. The methodcan also include moving the laser beam in the movement path in order tocreate the corneal pocket having the specific pocket shape.

In accordance with another aspect of the present invention, the methodcan include moving the laser toward the middle of the cornea tocompensate for astigmatic effect. The method can also include using alaser with an energy output in a range between approximately 0.2microjoules and 1.5 microjoules. The laser can also have a spot size ina range of approximately 0.2 to 4.0 microns and the corneal pocket canbe positioned at a depth in a range of approximately 220 microns to 350microns. Additionally, the laser can have multiple laser beam spots andthe space between the spots can be eliminated.

There has thus been outlined, rather broadly, certain embodiments of theinvention in order that the detailed description thereof herein may bebetter understood, and in order that the present contribution to the artmay be better appreciated. There are, of course, additional embodimentsof the invention that will be described below and which will form thesubject matter of the claims appended hereto.

In this respect, before explaining at least one embodiment of theinvention in detail, it is to be understood that the invention is notlimited in its application to the details of construction and to thearrangements of the components set forth in the following description orillustrated in the drawings. The invention is capable of embodiments inaddition to these described and of being practiced and carried out invarious ways. Also, it is to be understood that the phraseology andterminology employed herein, as well as the abstract, are for thepurpose of description and should not be regarded as limiting.

As such, those skilled in the art will appreciate that the conceptionupon which this disclosure is based may readily be utilized as a basisfor the designing of other structures, methods and systems for carryingout the several purposes of the present invention. It is important,therefore, that the claims be regarded as including such equivalentconstructions insofar as they do not depart from the spirit and scope ofthe present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a laser surgery apparatus for laser surgery to createan intracorneal pocket in accordance with an embodiment of theinvention.

FIG. 2 is a sectional view of the anterior portion of the eye having anintracorneal lens disposed therein, according to an embodiment of theinvention.

FIG. 3 illustrates a sectional view of the anterior portion of an eyehaving an implant disposed within the cornea of the eye according to anembodiment of the invention.

FIG. 4 illustrates a series of steps involved in a method for insertinga lens into the cornea of the patient.

FIGS. 5A and 5B illustrate incisions in a cornea and a corneal pocket inaccordance with an embodiment of the invention.

FIGS. 6A and 6B illustrate incisions in a cornea in accordance with anembodiment of the invention.

FIG. 7 illustrates a top down view of a corneal pocket in accordancewith an embodiment of the invention.

FIGS. 8A and 8B illustrate a 3-dimensional path for the laser beam inaccordance with an embodiment of the invention.

FIG. 9 illustrates a path for movement of the laser beam in accordancewith an embodiment of the invention.

DETAILED DESCRIPTION

The invention will now be described with reference to the drawingfigures, in which like reference numerals refer to like partsthroughout. An embodiment in accordance with the present inventionprovides an apparatus and method for creating a flap or pocket in thecornea. This lens or pocket preferably is created by a laser used inconventional lasik surgery.

FIG. 1 illustrates a laser surgery apparatus 10 for laser surgery tocreate an intracorneal pocket in accordance with an embodiment of theinvention. The laser surgery apparatus 10 can include a laser source 12which can generate and control, using software, a source beam 14 havinga continuous train of laser pulses of substantially constant pulseduration and pulse energy. In one embodiment of the laser surgeryapparatus 10, a source beam 14 can take the form of a femtosecond or ananosecond laser. The source beam 14 can also have wavelength greaterthan 800 nanometers and a pulse energy in a range of approximately 0.2mu·I to 1.5 mu·I. Using less energy for the pulse is preferable, but canbe any level of energy suitable for creating the corneal pocket.

The laser surgery apparatus 10 further includes an optical system 16 forforming a shaped laser beam 18 and directing the shaped laser beam 18toward and into the cornea 28 of an eye 22. The laser beam 18 can beprogrammed with a computer to determine the path of the laser beam 18over the patient's eye. Additionally, the laser beam 18 can beconfigured to follow a three-dimensional path to cut and separate thecornea to form a pocket for the insertion of the lens.

FIG. 2 is a sectional view of the anterior portion of the eye 22 havingan intracorneal lens 26 disposed therein, according to an embodiment ofthe invention. In the embodiment of the invention shown in FIG. 2,intracorneal lens 26 may be disposed within a cornea 28 of the eye 22,which may partially enclose the anterior chamber 30 of the eye 22. Alsoshown in FIG. 2 is an iris 32. In accordance with an embodiment of theinvention, lens 26 may be inserted within cornea 28 following formationof a corneal pocket 29, which may be formed using a laser surgeryapparatus 10 as shown in FIG. 1.

Intracorneal lens 26 is not restricted to the configuration shown in thedrawings, but may have various shapes, such as circular or oval. In someembodiments, intracorneal lens 26 may have a doughnut-likeconfiguration. The size and shape of intracorneal lens 26 may, in somecases, determine the size and shape of the corneal pocket.

The intracorneal lens 26 preferably may be formed of a biocompatiblematerial that permits sufficient gas diffusion to allow adequateoxygenation of internal eye tissues. Such materials may includesilicone, hydrogels, urethanes or acrylics. It also may be desirablethat the lens be made of a hydrophilic material which swells somewhatwhen hydrated. Such materials, for example, hydrogels, are well knownand are used in some present contact lenses.

The optical characteristics of intracorneal lens 26 may be selected forcorrecting various visual deficiencies, including without limitation:myopia (short sightedness), hypermetropia (long sightedness), presbyopiaand astigmatism. As an example, intracorneal lens 26 may have a diopterpower or value in the range of from +15 to −30. Intracorneal lens 26 maybe customized for a particular patient to provide opticalcharacteristics to correct a specific visual defect of a patient.Intracorneal lens 26 may be multifocal, may be provided as anoff-the-shelf unit with pre-determined optical characteristics and mayhave zones with optical power and zones without optical power. It is tobe understood that the present invention is not limited to treatment ofthe aforementioned visual defects, and that treatment of other eyeconditions is also within the scope of the invention.

FIG. 3 shows a cross section of a cornea 28 having a corneal pocket 29formed by a laser surgery apparatus 10 in accordance with one embodimentof the invention. Cornea 28 has an anterior surface 31 and a posteriorsurface 33. Corneal pocket 29 may be formed by photo disruption usinglaser beam 18 from a laser source 12.

The corneal pocket 29 may be formed with a thickness and shape thatconforms to the surfaces of the intracorneal lens 26. For example, theinterior surfaces of the corneal pocket 29 may be convex, concave,planar or irregular. The edges of the corneal pocket 29 may form anoutline having various shapes depending on the desired outcome and theshape of the intracorneal lens 26. The various configurations of cornealpockets can be adapted to be used with lenses of various shapes andsizes. The corneal pocket can also be configured to facilitate theinsertion of the lens. and minimize the size of the incision forimproved post-surgical healing of the cornea. The corneal pocket canalso include an entry channel 34 that may be cut into the cornea 28after the corneal pocket 29 is formed. Entry channel 34 may permit theinsertion of the intracorneal lens 26 into the corneal pocket 29.

FIG. 4 schematically represents a series of steps involved in a processfor creating a corneal pocket and inserting a lens in the cornea of apatient, according to one embodiment of the invention. The process maybegin with the step 74 of providing an intracorneal lens 26. Theintracorneal lens 26 may or may not have optical power depending on thepurpose of the intracorneal lens 26. In step 78 a corneal pocket 29 maybe formed. This may be done using the laser surgery apparatus 10 shownin FIG. 1. In particular. a laser source 12 being controlled by anoptical system 16 may be used to focus a laser beam 18 within thecorneal tissue. The laser beam 18 will cut and separate a region of thecornea tissue in the area of the focus of the laser beam 18. The focusof the laser beam 18 may then be moved laterally by hand to cut a layerof corneal tissue. While the focus of the laser beam 18 is being movedlaterally, it may be maintained a fixed depth within the cornea usingknown laser surgical techniques. The focus of the laser beam 18 may beeasily, quickly and accurately moved laterally by controlled softwarewithin the confines of the pocket region without the risk of cuttingoutside the desired area defined by the software.

The thickness of the corneal pocket created using the above techniqueswill be about the size of the diameter of the laser beam 18 focal point.In some cases, depending on the thickness and shape of the intracorneallens 26, additional tissue may be cut at different depths within thecornea 28.

In step 80 an entry channel 34 may he formed. This may he accomplishedusing the laser source 12 or may be formed using a conventional scalpel.Entry channel 34 may provide a means for insertion of the intracorneallens 26 and also will allow the release of gasses created by laserablation when the intracorneal pocket 29 is formed.

The intracorneal lens 26 may then be inserted into the intracornealpocket 29 in step 82. Step 82 may further involve temporarily deformingthe intracorneal lens 26 before it is introduced into the cornea 28. Theintracorneal lens 26 may be deformed by rolling, folding, and the like.The intracorneal lens 26 may have prescribed memory characteristics thatallow it to return to its original size and configuration afterinsertion into the cornea 28, while retaining its desired opticalcharacteristics. The intracorneal lens 29 may be made of a hydrophilicmaterial which swells when hydrated. The lens may be inserted fullyhydrated to elastically fit into a corneal pocket, or while at leastpartly dehydrated such that subsequent hydration helps secure the fit inthe pocket.

FIGS. 5A and 5B illustrate incision patterns in a cornea, in accordancewith an embodiment of the invention. As illustrated in FIGS. 5A and 5B,an entry incision 102, 202 can be made on the cornea 100, 200. The entryincision 102, 202 is shown as being positioned on a rightward edge ofthe cornea 100, 200, in FIGS. 5A and 5B. However, the entry incision102, 202 can be positioned in any suitable portion of the cornea 100,200. A circular pocket 104, 204 can also be formed in the cornea. Aninsertion tunnel 106, 206 can be positioned between the entry incision102 and the pocket 104. Additionally, as illustrated in FIG. 5A, asecond tunnel 108 can be positioned to the left of the circular pocket104. Alternately, as shown in FIG. 5B, relaxing incisions 210 can bemade in the cornea 200, in order to ease the insertion of the corneallens and reduce astigmatism.

FIGS. 6A and 6B also illustrate incision patterns in a cornea, inaccordance with an embodiment of the invention. As illustrated in FIGS.6A and 6B, an entry incision 302, 402 can be made on the cornea 300,400. The entry incision 302, 402 is shown as being positioned on arightward edge of the cornea 300, 400. in FIGS. 6A and 6B. However, theentry incision 302, 402 can be positioned in any suitable portion of thecornea 300, 400. An insertion tunnel 306, 406 can be positioned leftwardof the entry incision 302. 402, and can extend across the cornea 300,400. Additionally, as shown in FIG. 6B, relaxing incisions 410 can bemade in the cornea 400, in order to ease the insertion of the corneallens and reduce a preexisting astigmatism.

FIG. 7 illustrates a top down view of the same corneal pocket 29, Thepocket and the relaxing incisions can be made with a femtosecond ornanosecond laser having an energy profile in a range of approximately0.2 microjoules to 1.5 microjoules. Any suitable energy level can beused, however lower energy output is preferable. Additionally, the laserbeam can have a spot size in a range of approximately 0.2 microns to 4.0microns. The depth of the cut can be in a range of approximately 220microns to 350 microns. It should be noted that if the cut is too deepthe structure of the cornea can become less stable. The pocket profile29 shown in FIG. 8 can be used to minimize distortion of the patient'svision through the newly implanted lens. However, if the patient suffersfrom astigmatism the cut can be moved toward the middle of the cornea inorder to minimize the astigmatic effect.

FIGS. 8A, 8B, and 9 illustrates a path for the laser beam and adirection for the movement of the laser beam, in accordance with anembodiment of the invention. More particularly, FIG. 8A illustrates aside view of the path for the laser beam and FIG. 8B illustrates a topdown view of the path. The pocket 229 can be formed and an adjacententry channel 234 can be formed in order to allow the insertion of theintracorneal lens into the corneal pocket 229. While FIGS. 8A and 8Billustrate a path for the laser beam, this is simply one example of thepath that can be used to form the pocket 229 and the entry channel 234.Any path that is suitable for the purpose of forming a pocket can beused. Preferably, the path the laser is moved in is curvilinear tofollow the natural curvature of the eye. FIG. 9 illustrates the laserbeam 240 moving across an axis of the eye. The laser beam 240 can have asingle beam or multiple beams creating a single laser spot or multiplelaser spots respectively. Additionally, if the laser beam used hasmultiple spots, preferably there is no space between the spots of thelaser beam.

As can be appreciated by those skilled in the art, the present inventionmay provide a method for correcting the vision of a patient with anintracorneal lens 26 that may be easily inserted into a corneal pocket29. The corneal pocket 29 may be created using a laser source 12 or maybe created using other forms of electromagnetic radiation. The creationof the corneal pocket 29 is facilitated by the use of software thatprevents the laser beam 18 from cutting and separating tissue outsidethe boundary of a desired shape. A variety of corneal pocketconfigurations may be used to accommodate various corneal lens shapesand sizes. Other surgical procedures, such as arcuate cuts, may also bemade using the techniques of the invention.

The many features and advantages of the invention are apparent from thedetailed specification, and thus, it is intended by the appended claimsto cover all such features and advantages of the invention, which fallwithin the true spirit, and scope of the invention. Further, sincenumerous modifications and variations will readily occur to thoseskilled in the art, it is not desired to limit the invention to theexact construction and operation illustrated and described, andaccordingly, all suitable modifications and equivalents may be resortedto, falling within the scope of the invention.

1. A method for creating a corneal pocket and an entry channel forinserting and positioning an intracorneal lens in the corneal pocket,the method comprising: providing a low-energy femtosecond laserconfigured to create the corneal pocket and the entry channel;positioning the laser proximate to a cornea such that it can be used tocreate the corneal pocket; receiving an input for a generallycurvilinear movement path and a first laser energy output in a rangebetween approximately 0.2 microjoules and 1.5 microjoules for the laserto form the corneal pocket in the cornea and having a specific pocketshape and a thickness conforming to predefined surfaces of anintracorneal lens to be inserted into the corneal pocket; focusing alaser beam from the laser to a predetermined depth in the range of about220 microns to 350 microns within the cornea between an anterior surfaceand a posterior surface of the cornea such that the laser beam ablatescorneal tissue at a focal point at the predetermined depth; moving thelaser beam in the generally curvilinear movement path in order to createthe corneal pocket having the specific pocket shape and a thicknessabout the size of diameter of the laser beam focal point; forming theentry channel into the corneal pocket with the laser beam, wherein theentry channel is at an obtuse angle from the corneal pocket toward anentry incision on the cornea.
 2. The method of claim 1, furthercomprising programming and operating the laser to have spot size in arange of about 0.2 to 4.0 microns.
 3. The method of claim 1, furthercomprising providing a laser with multiple laser beam spots.
 4. Themethod of claim 3 further comprising eliminating space between the laserbeam spots.
 5. The method of claim 1 further comprising forming arelaxing incision in a region of the cornea outside of the cornealpocket and the entry channel in order to ease the insertion of theintracorneal lens into the corneal pocket.
 6. The method of claim 4,wherein the forming of the relaxing incision includes forming at leasttwo generally arc shaped incisions that can reduce a preexistingastigmatism.
 7. A method for creating a corneal pocket and an entrychannel for inserting and positioning an intracorneal lens in thecorneal pocket, the method comprising: using a low-energy femtosecondlaser configured to create the corneal pocket; positioning the laserproximate to a cornea such that it can be used to create the cornealpocket; determining a generally curvilinear movement path and an energyoutput in a range between approximately 0.2 microjoules and 1.5microjoules for the laser in order to form the corneal pocket in thecornea having a specific shape and a thickness conforming to predefinedsurfaces of an intracorneal lens to be inserted into the corneal pocket;configuring the laser to follow the generally curvilinear movement pathusing a positioning software; focusing a laser beam from the laser to afocal point at a predetermined depth in a range of approximately 220microns to 350 microns within the cornea between an anterior surface anda posterior surface of the cornea such that the laser beam cuts andseparates corneal tissue; operating the laser beam in the generallycurvilinear movement path in order to create the corneal pocket havingthe specific shape and a thickness about the size of a diameter of thelaser beam focal point; and forming the entry channel into the cornealpocket with the laser beam, wherein the entry channel is at an obtuseangle from the corneal pocket toward and entry incision on the cornea.8. The method of claim 7 wherein the diameter of the laser beam focalpoint is the laser's spot size being in a range of about 0.2 to 4.0microns.
 9. The method of claim 7 further comprising providing a laserwith multiple laser beam spots.
 10. The method of claim 9 furthercomprising eliminating space between the laser beam spots.
 11. Themethod of claim 7 further comprising forming at least one arc shapedrelaxing incision(s), using an energy output that is less than thedetermined energy output used to create the cornel pocket in a region ofthe cornea outside the corneal pocket and the entry channel
 12. A methodfor creating a corneal pocket and an entry channel for inserting andpositioning an intracorneal lens in the corneal pocket using a lowenergy femtosecond laser, the method comprising: receiving inputs forprogramming a three-dimensional generally curvilinear movement path andan energy output in a range between approximately 0.2 microjoules and1.5 microjoules for the low-energy femtosecond or a nanosecond laserconfigured to create the corneal pocket; transmitting instructions for athree-dimensional generally curvilinear movement path for the laser inorder to form the corneal pocket having a specific shape and thicknessconforming to a predetermined intracorneal lens to be inserted; focusinga laser beam from the laser to a focal point at a predetermined depth ina range of approximately 220 microns to 350 microns within the corneabetween an anterior surface and posterior surface of the cornea suchthat the laser beam ablates corneal tissue at the predetermined depthusing the energy output input received; forming the entry channel intothe corneal pocket with the laser beam.
 13. The method of claim 12further comprising configuring the laser to have spot size in a range ofabout 0.2 to 4.0 microns.
 14. The method of claim 12 further comprisingconfiguring the laser to emit multiple laser beam spots.
 15. The methodof claim 14 wherein the space between the multiple laser beam spots canbe eliminated before the insertion of the intracorneal lens.
 16. Themethod of claim 12 further comprising: forming a relaxing incision in aregion of the cornea outside of the corneal pocket and the entry channelusing an energy output that is less than the energy output inputreceived to create the corneal pocket.
 17. The method of claim 16wherein the relaxing incision is formed in order to ease the insertionof the intracorneal lens into the corneal pocket.
 18. The method ofclaim 16 wherein the relaxing incision includes at least one arc shapedincision formed in order to correct a pre-existing astigmatism.
 19. Amethod for forming a corneal incision comprising: providing a low energyfemtosecond laser configured to create a corneal incision; positioningthe laser proximate to the cornea such that it can be used to create acorneal incision; determining a three-dimensional movement path for thelaser in order to form the corneal incision having a specific shapewherein the movement path follows a generally curvilinear path which isdetermined by programming a controlling computer to create the specificshape; moving the laser under control of the programmed computer tothereby cut and separate corneal tissue.
 20. The method of claim 19further comprising focusing a laser beam from the laser to a focal pointat a predetermined depth in a range of approximately 220 microns to 350microns within the cornea between an anterior surface and posteriorsurface of the cornea such that the laser beam ablates corneal tissue ata focal point at the predetermined depth.
 21. The method of claim 20,further comprising programming and operating the laser to have spot sizein a range of about 0.2 to 4.0 microns.
 22. The method of claim 19,further comprising providing a laser with multiple laser beam spots. 23.The method of claim 22 further comprising eliminating space between thelaser beam spots.